Incandescent electric lamp



J. A. HEANY.

INCANDESCENT ELECTRIC LAMP.

APPLICATION FILED JULY 29,1916.

Patented Dec. 6, 1921.

tii NIT-151D STATES PATENT rm;

JO N'ALLEN (HEA'NY, or NEW YORK, a. r.

To all whom it may concern:

Be it known that I, J oHN ALLEN HEANY,

1 a citizen of the United States, residing in the city of New York, county of New York, and'State of New York, have invented certain new and useful Improvements in Incondescent Electric Lamps; and I do hereby declare the following to be a full, clear, and exact description of'the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates. to incandescent electric lamps and has for its object to provide an improved glower for use therein and also an improved method of making the glower.

In its preferredform, the. glower compulses a base of porous refractory material,

panying drawing, in which such, for example, as zirconium oxid, thorium oxid, magnesium oxid, or the like, or

mixtures of these compounds impregnated wholly or in part with a highly refractory metal, such. as tungsten,. titanium, molybdeum, vanadium, tantalum or the like having a higher fusing point than the platinum group, or mixtures of these metals. Although the size and shape of the glower are immaterial, so far as the broader aspects of the invention are concerned, it is preferably made substantially cylindrical inshape, of relatively short length and large diameter, as compared with the filament of the ordinary strung lamp, for the purpose of v partly impregnated with the refractory lid metal. I p

The exact manner of mounting the glower [inithe lamp is immaterial, but 1t is preferably mounted as shown in Fig. 1, in which the usual bulb is indicated at 1 with which there is associated the ordinary threaded metallic base 2. The base. 2 is electrically 3 connected with the lead wires 3 and l which Specification of Letters latent.

IN'CANDESGENT ELECTRIC LAMP.

Patented Dec. 6, 1921..

Application filed July 29, 1916. Serial No. 111,997.

serve to support the glower, denoted generally by the reference character A. The bulb l is preferablyfilled with an inert gaseous medium, such as nitrogen, mercury vapor or the like, having low thermal conductivity for the purpose of keeping down the convection losses, and capable of preventing to as great an extent as possible, evaporation of the glower. l

The porous base shown at a in Figs. 2 and 3 is, as above stated, made. of some refractory compound, such as zirconium oxid, thorium oxid or a similar porous refractory material of very low conductivity, but which possesses great strength even at the operating temperature. It is obvious that if desired, several of these compounds may be used in conjunction to form the base. In the manufacture of the glower, the refractory compound or compounds are made into a plastic mass molded to the proper shape, and then baked to the required degree. This baking may be effected at extremely high temperature and for such a length of time that the base will be completely shrunk to its final form, or else the base may be baked only to such an extent that it is rendered sufliciently hard to be handled and the final baking may be postponed until after the base is impregnated with the refractory metal.

The material used for impregnating the base may be either metal in a finely divided state, a solution of the metal, or a compound of the metal. If a metallic compound is used, the compound is converted into metal. If, for instance, it be desired to impregnate the base with-a refractory metal, such as tungsten, a solution may be made of ammonium tungstate which is soluble in water. The porous base may be steeped in this solution, dried and the solution converted to metallic tungsten by heat and hydrogen gas. A solution of colloidal ammonium paratungstate may also be used and after the porous base is steeped in this solution, it is dried and treated by heat and hydrogen gas which reduces the tungsten compound to metallic tungsten. It is also possible to impregnate the porous refractory base with a pseudo colloidal metal, such as those produced by arcing in various li uids.

t is obvious that the entire body of the refractory base a may be impregnated with of may be impregnated, as shown at b in Fig. 3. It is also obvious that the porous base may be subjected to as many steeplng' operations as desired, in order to vary the content of refractory metal in the final glower. A very small amount of metal may be incorporated in the refractory base by utilizing a weak solution of the metallic compound, so it is, therefore, evident that the process is very flexible, in that the quantity of metal incorporated in the base may be readily varied to vary the conductivity of the glower. If it be desired to'impregnate the porous base with a metallic alloy, the base may be treated with solutions of -two or more metallic compounds.

After the steeping operatlon of the porous base, the same is baked at a high temperature and for a sufficient length of time to shrink the glower to its final form before, it is mounted in the bulb, provided this baking operation is not performed be- 1 ing its strength or materially increasing its conductivity, because the support a possesses great strength, even at the highest temperatures at which the lamp is operated, and the current in traversing the glower passes onl through the conductive refractory meta incorporated in the base. The refractory metal, therefore, serves as .the resistor and heats the base of refractory compound to incandescence.

Although the glower' is represented in the drawing as being of solid cylindrical shape,

it is obvious that-it can be made in various other shapes.

What I claim is The process of making a glower for incandescent electric lamps, which consists in moldin into desired shape a plastic mass of higl y refractory material, treating said mass to produce a stron porous body, impregnatin the said b0 y with a solution of a meta ic compound,- the metal of which incandesces at the temperature at which platinum volatilizes, and then reducing the compound to metal byheating the glower in the presence of hydrogen.

In testimony whereof I afiix 'my signature.

JOHN ALLEN HEANY. 

